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x86: make 'mem=' option to work for efi platform

PATCH In review Wen Congyang 2 participants 2 messages Nov 13, 2012 – Jan 3, 2013

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x86 EFI
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Wen Congyang

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#0 lore raw

PATCH v4 1/1 x86: make 'mem=' option to work for efi platform

Current mem boot option only can work for non efi environment. If the user specifies add_efi_memmap, it cannot work for efi environment. In the efi environment, we call e820_add_region() to add the memory map. So we can modify __e820_add_region() and the mem boot option can work for efi environment.

Note: Only E820_RAM is limited, and BOOT_SERVICES_{CODE,DATA} are always mapped(If its address >= mem_limit, the memory won't be freed in efi_free_boot_services()).

Changelogs from v3 to v4:
1. address the comment from Matt Fleming <[email protected]>:
a. only ignoring E820_RAM entries that are above the mem_limit b. don't ignore E820_RAM entries which are BOOT_SERVICES_{CODE,DATA} regions

Signed-off-by Wen Congyang <[email protected]>
---
 arch/x86/include/asm/e820.h |  2 ++
 arch/x86/kernel/e820.c      | 72 +++++++++++++++++++++++++++++++++++++++------
 arch/x86/platform/efi/efi.c | 15 ++++++++--
 3 files changed, 77 insertions(+), 12 deletions(-)
arch/x86/include/asm/e820.h +2 -0
index 3778256..c1f31ee 100644
@@ -84,6 +84,8 @@ extern unsigned long pci_mem_start;
 extern int e820_any_mapped(u64 start, u64 end, unsigned type);
 extern int e820_all_mapped(u64 start, u64 end, unsigned type);
 extern void e820_add_region(u64 start, u64 size, int type);
+extern void e820_add_limit_region(u64 start, u64 size, int type);
+extern void e820_adjust_region(u64 *start, u64 *size);
 extern void e820_print_map(char *who);
 extern int
 sanitize_e820_map(struct e820entry *biosmap, int max_nr_map, u32 *pnr_map);
arch/x86/kernel/e820.c +63 -9

128 lines not on this page · raw message

arch/x86/platform/efi/efi.c +12 -3
index ad44391..7592163 100644
@@ -314,10 +314,17 @@ static void __init do_add_efi_memmap(void)
 		int e820_type;
 
 		switch (md->type) {
-		case EFI_LOADER_CODE:
-		case EFI_LOADER_DATA:
 		case EFI_BOOT_SERVICES_CODE:
 		case EFI_BOOT_SERVICES_DATA:
+			/* EFI_BOOT_SERVICES_{CODE,DATA} needs to be mapped */
+			if (md->attribute & EFI_MEMORY_WB)
+				e820_type = E820_RAM;
+			else
+				e820_type = E820_RESERVED;
+			e820_add_region(start, size, e820_type);
+			continue;
+		case EFI_LOADER_CODE:
+		case EFI_LOADER_DATA:
 		case EFI_CONVENTIONAL_MEMORY:
 			if (md->attribute & EFI_MEMORY_WB)
 				e820_type = E820_RAM;

@@ -342,7 +349,7 @@ static void __init do_add_efi_memmap(void)
 			e820_type = E820_RESERVED;
 			break;
 		}
-		e820_add_region(start, size, e820_type);
+		e820_add_limit_region(start, size, e820_type);
 	}
 	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 }

@@ -448,6 +455,8 @@ void __init efi_free_boot_services(void)
 		    md->type != EFI_BOOT_SERVICES_DATA)
 			continue;
 
+		e820_adjust_region(&start, &size);
+
 		/* Could not reserve boot area */
 		if (!size)
 			continue;
Signature · 1 line
1.8.0
#1 lore raw
Quoted 14 lines · Wen Congyang
arch/x86/platform/efi/efi.c +2 -2
index ad44391..7592163 100644
@@ -314,10 +314,17 @@ static void __init do_add_efi_memmap(void)
 		int e820_type;
 
 		switch (md->type) {
-		case EFI_LOADER_CODE:
-		case EFI_LOADER_DATA:
 		case EFI_BOOT_SERVICES_CODE:
 		case EFI_BOOT_SERVICES_DATA:
+			/* EFI_BOOT_SERVICES_{CODE,DATA} needs to be mapped */
+			if (md->attribute & EFI_MEMORY_WB)

arch/x86/platform/efi/efi.c static void __init do_add_efi_memmap(void) · line 330

Quoted 10 lines
arch/x86/platform/efi/efi.c +7 -0
+				e820_type = E820_RAM;
+			else
+				e820_type = E820_RESERVED;
+			e820_add_region(start, size, e820_type);
+			continue;
+		case EFI_LOADER_CODE:
+		case EFI_LOADER_DATA:
 		case EFI_CONVENTIONAL_MEMORY:
 			if (md->attribute & EFI_MEMORY_WB)
 				e820_type = E820_RAM;

This chunk seems to cause one of my EFI machines to crash. If I include EFI_LOADER_{CODE,DATA} in the same clause as EFI_BOOT_SERVICES* things work. I'm not sure why that is since the e820_type is E820_RAM.

Maybe I need to use memmap= too when booting?